[PATCH 05/19] block: rework requesting modules for unclaimed devices

From: Christoph Hellwig
Date: Sun Aug 30 2020 - 02:27:20 EST


Instead of reusing the ranges in bdev_map, add a new helper that is
called if no ranges was found. This is a first step to unpeel and
eventually remove the complex ranges structure.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/genhd.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 0ae6210e141ee5..00164304317cfa 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1035,6 +1035,13 @@ static ssize_t disk_badblocks_store(struct device *dev,
return badblocks_store(disk->bb, page, len, 0);
}

+static void request_gendisk_module(dev_t devt)
+{
+ if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
+ /* Make old-style 2.4 aliases work */
+ request_module("block-major-%d", MAJOR(devt));
+}
+
static struct gendisk *lookup_gendisk(dev_t dev, int *partno)
{
struct kobject *kobj;
@@ -1059,6 +1066,14 @@ static struct gendisk *lookup_gendisk(dev_t dev, int *partno)
probe = p->probe;
best = p->range - 1;
*partno = dev - p->dev;
+
+ if (!probe) {
+ mutex_unlock(&bdev_map_lock);
+ module_put(owner);
+ request_gendisk_module(dev);
+ goto retry;
+ }
+
if (p->lock && p->lock(dev, data) < 0) {
module_put(owner);
continue;
@@ -1297,15 +1312,6 @@ static const struct seq_operations partitions_op = {
};
#endif

-
-static struct kobject *base_probe(dev_t devt, int *partno, void *data)
-{
- if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
- /* Make old-style 2.4 aliases work */
- request_module("block-major-%d", MAJOR(devt));
- return NULL;
-}
-
static void bdev_map_init(void)
{
struct bdev_map *base;
@@ -1317,7 +1323,6 @@ static void bdev_map_init(void)

base->dev = 1;
base->range = ~0 ;
- base->probe = base_probe;
for (i = 0; i < 255; i++)
bdev_map[i] = base;
}
--
2.28.0